{System: I am having a bit of trouble calculating this. And I am reposting this sense I don’t think it’s fair to give only a little amount of points.. so I am making it higher! Please help me with this}

Total volume of light-blue paint:
[tex]\left(4+\dfrac38\right)+\left(6+\dfrac18\right)=10+\dfrac48=10+\dfrac12[/tex]
Divide by [tex]\dfrac14[/tex] to find how many containers he can divided this total into:
[tex]\dfrac{10+\frac12}{\frac14}=4\left(10+\dfrac12\right)=40+\dfrac42=40+2=42[/tex]
so the answer is B.